TOKYO — At his lowest point, Shinzo Abe lost his health and his reputation. He’d gotten his chance to lead Japan and lasted just 366 days. His aides scattered. He was jeered in public. When he boarded a plane one day, a passenger in the same row asked to move, according to a recent book.

Just seven years later, not only is Abe back as prime minister but he’s also more powerful than any of his recent predecessors, with an approval rating near 60 percent. His resurgence is every bit as improbable as his country’s.

Although political comebacks make for popular theater in Washington — think Bill Clinton or Newt Gingrich — they are far less common in Japan, where politics is driven more by party than personality. For decades, Japan has been governed by ­baton-passing prime ministers who slink off quickly and quietly. Abe’s exit in 2007 seemed as final as any.

Instead, Abe has pulled off a political resurrection unlike any here since World War II, returning from humiliation with a new — and resonant — message about a stronger Japan. The Japan of Abe is both confident and adversarial, shaking off long-standing deflation and increasingly confronting China over contested territory.

If Abe’s personal comeback makes a handy emblem for those broader changes, he has rarely discussed in detail his journey back to the job, a period that included a week-long carrot-juice fast, a marathon of living-room meet-and-greets back home and a series of backroom study sessions involving like-minded conservatives in Tokyo.

Aides, advisers and friends say Abe emerged from that period as a savvier politician, slightly hardened in his conservative beliefs but less willing to burn political capital by pursuing them en masse. He also studied one of his weak points, economics, and came away believing that Japan’s central bank had been mismanaging its policies for decades. He grew that belief into a radical — and so far successful — strategy of spending and monetary easing known as Abenomics.

“Nobody else had reached that level of embarrassment,” said Yoshimasa Suenobu, a friend and journalist who often played golf with Abe during his years out of office, “so he must have eventually concluded he had nothing else to lose.”

Rehabilitation

Barring unforeseen obstacles, Abe, who retook power in December 2012, is a lock to hold his job through at least 2016. That would give him a term longer than all but two of Japan’s 23 prime ministers since the early 1970s.

Abe’s first term was a calamity: While the nation fretted about its economy, Abe called for “a more beautiful country” that valued its heritage and nature. Four cabinet ministers resigned, another committed suicide, and Abe’s popularity sputtered because of several small scandals. Ultimately, it was a bowel disease — ulcerative colitis — that brought him down. After resigning, ashen-faced, he checked into a Tokyo hospital and stayed for weeks.

Abe’s initial goals at that point were to get healthy and stay alive politically, his advisers say. To regain full strength, Abe tried supplements, a juice fast, even hiking. But it was an ­anti-inflammatory drug new to the Japanese market — Asacol — that did the trick.

Abe regained his health just in time to fight for his career. He’d served in Japan’s parliament since 1993, representing his home district of Yamaguchi, at the western tip of Japan’s main island. Abe had strong odds of reclaiming his seat — his Liberal Democratic Party (LDP) dominates the region — but he wanted to do so decisively.

If he failed to do that, Abe’s plan was to retire from politics at the end of his new four-year term, he said in a November interview with Suenobu, broadcast by BS Asahi.

“Back then, people said my political career was almost over. I needed to start from zero,” Abe said in the interview.

Abe had returned to Yamaguchi just once in his year as prime minister, but as he geared up for reelection in 2009, he flew in almost every weekend, his aides say. He did morning stretches with senior citizens, he spoke to elementary school classes, he showed up at ribbon-cuttings and karate events.

“He specifically said he wanted to meet local people and talk,” said Tsuyoshi Hatamura, an aide at Abe’s local office.

Abe had a built-in advantage in Yamaguchi: his famous family. Abe’s grandfather Nobusuke Kishi had signed the U.S.-Japan security treaty as a postwar prime minister; earlier, he had spent three years in jail, arrested but never charged as a war criminal. Abe’s father, Shintaro, had served as foreign minister at the height of Japan’s 1980s economic boom.

Advisers say that Abe relished grass-roots politicking in an area where he was still remembered as political royalty. When the election came, he won 64 percent of the vote.

With that outcome, “he was able to regain a strong will,” said Abe’s younger brother, Nobuo Kishi, who now serves as Japan’s vice foreign minister.

A ‘critical’ malaise

During his first term as prime minister, Abe had been an ­ill-fitting outlier. He was the youngest Japanese leader to hold office since World War II and decidedly the most right-wing.

His revival reflects not just his own efforts, but a fundamental sense of crisis that had developed among the Japanese in recent years. The country seemed at a loss in dealing with its economy and in dealing with China, the looming power in Asia. Desperate voters ushered in a new party in 2009 — Abe’s Liberal Democrats were sent to the sideline after a half-century of near-uninterrupted rule — but the Democratic Party of Japan (DPJ) proved even more ineffective. It botched a diplomatic standoff with Beijing and struggled with the overwhelming job of recovery after the 2011 tsunami and nuclear meltdowns.

For a nation with a growing sense of alarm, Abe’s hawkish views suddenly seemed a good fit. Since retaking office, Abe has occasionally described Japan’s malaise as “severe” or “critical,” saying this is its last good chance to regain vitality.

During his years out of power, Abe took several critical steps to rebuild his support within his party.

He chaired a study group of conservatives that discussed a set of sharper priorities for the LDP, including education reform, expanded diplomacy and a loosening of pacifist restrictions on the military. Within the group, called Create Japan, Abe was seen as one of the true believers, with views inherited from his grand­father.

“Many members of the study group believed Abe was the one who could lead us back,” said Seiichi Eto, a Create Japan member and parliamentarian who is a special adviser to the prime minister.

The small meetings helped Abe within his party, but it was a different area of study — economics — that helped him ultimately win the support of a nation more interested in pensions and portfolios than in right-wing ideology.

In 2011 and 2012, Abe consulted closely with policy experts, including Yoichi Takahashi, a former Finance Ministry official, and Koichi Hamada, a professor emeritus of economics at Yale. They both believed that the Bank of Japan had long been too timid about using its most powerful tool — printing cash — to end the two-decade cycle of deflation, the vicious cycle of falling wages and prices that reduces consumer appetite.

Both Hamada and Etsuro Honda, who became a special adviser to the Abe cabinet, say they were impressed by Abe’s understanding of macroeconomics. Abe became a fluent and frequent critic of the Bank of Japan.

“Monetary policy is very technical, and it’s not something many politicians are interested in,” Honda said. “But he built up a vision: Tackle the economy, and then go on to deal with other issues.”

A key decision

Ultimately, Abe’s comeback was telegraphed months ahead of time. The ruling DPJ had squandered its popularity by 2012, and the Liberal Democrats, almost by default, were again the party of choice in general elections.

Abe’s main question was whether to contend for the LDP presidency — a key decision, because the head of the ruling party becomes prime minister. Several relatives, including his mother, Yoko, were opposed, according to “Fate of the Nation,” a book by Eitaro Ogawa about Abe’s cabinet that was published in June 2013. But Abe’s wife, Akie, gave her approval.

Abe won the LDP presidency in a close September 2012 race. Three months later, he was running the country. “Japan is back,” he said in many of his speeches.

“If I am unable to make Japan a great country and a robust country this time around,” Abe said, “then there is no meaning to the life I have lived thus far.”

Yuki Oda contributed to this report.

Chico Harlan covers personal economics as part of The Post's financial team.

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